1. Field of the Invention
The present invention relates in general to a pedal device such as a brake pedal device and an accelerator pedal device, and more particularly to an improved adjustable pedal device wherein the non-operated position of an operating portion of a pedal is adjustable.
2. Discussion of Related Art
There is known an adjustable pedal device having a pedal including (a) a pivotal member which is supported by a bracket such that the pivotal member is pivotable about a support shaft, and (b) a pedal member disposed movably relative to the pivotal member to a selected one of a plurality of relative positions and having at its lower end an operating portion at which the pedal member is operated so that the pedal member and the pivotal member are pivoted together about the support shaft. JP-A-2-39216 discloses an example of an adjustable pedal device of this type for an automotive vehicle, wherein the non-operated position of the operating portion of the pedal member is adjustable in the longitudinal or running direction of the vehicle. The pivotal member is provided with a return spring (a torsion spring) for holding the operating portion of the pedal member at the presently selected non-operated position. When the non-operated position of the operating portion of the pedal member is adjusted, a lever length of the pedal which is a distance between the operating portion and the support shaft is changed, so that a force of resistance to a pivotal motion of the pedal from the non-operated position, which is produced by the return spring, is accordingly changed. To reduce an amount of change of this force of resistance (hereinafter referred to as “depression resistance force of the pedal”), the pedal device uses (i) an adjusting lever which is pivoted when the non-operated position of the pedal member is adjusted, and (ii) an adjusting spring which biases the adjusting lever and which is elongated or contracted with a result of changing its biasing force acting on the adjusting lever, whereby the amount of change of the depression resistance force is reduced.
However, the known adjustable pedal device constructed as described above requires the adjusting lever and the adjusting spring in addition to the return spring, resulting in undesirable increase in the number of the required components and the weight and cost of manufacture of the pedal device, and an undesirable increase in the structural complexity of the pedal device. Further, an electric motor provided to adjust the pedal is required to pivot also the adjusting lever while elongating or contracting the adjusting spring, so that the required size and capacity of the electric motor are increased, resulting in a further increase in the weight and cost of manufacture of the pedal device.